diff options
| author | Andre Przywara <andre.przywara@arm.com> | 2018-05-11 15:20:14 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-22 16:57:56 +0200 |
| commit | 9488d11728a6d945ce589cac6b6760cdb361e9c6 (patch) | |
| tree | 12ff071114e80cc6f6d1e1b61fb2f84f5adbe92b /virt | |
| parent | ad04996f0bb0a2bfc8468c04dacc40aed76de8ae (diff) | |
KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock
commit bf308242ab98b5d1648c3663e753556bef9bec01 upstream.
kvm_read_guest() will eventually look up in kvm_memslots(), which requires
either to hold the kvm->slots_lock or to be inside a kvm->srcu critical
section.
In contrast to x86 and s390 we don't take the SRCU lock on every guest
exit, so we have to do it individually for each kvm_read_guest() call.
Provide a wrapper which does that and use that everywhere.
Note that ending the SRCU critical section before returning from the
kvm_read_guest() wrapper is safe, because the data has been *copied*, so
we don't need to rely on valid references to the memslot anymore.
Cc: Stable <stable@vger.kernel.org> # 4.8+
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-its.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 31f562507915..1ebbf233de9a 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -208,8 +208,8 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq, u8 prop; int ret; - ret = kvm_read_guest(kvm, propbase + irq->intid - GIC_LPI_OFFSET, - &prop, 1); + ret = kvm_read_guest_lock(kvm, propbase + irq->intid - GIC_LPI_OFFSET, + &prop, 1); if (ret) return ret; @@ -339,8 +339,9 @@ static int its_sync_lpi_pending_table(struct kvm_vcpu *vcpu) * this very same byte in the last iteration. Reuse that. */ if (byte_offset != last_byte_offset) { - ret = kvm_read_guest(vcpu->kvm, pendbase + byte_offset, - &pendmask, 1); + ret = kvm_read_guest_lock(vcpu->kvm, + pendbase + byte_offset, + &pendmask, 1); if (ret) { kfree(intids); return ret; @@ -628,7 +629,7 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, int id) return false; /* Each 1st level entry is represented by a 64-bit value. */ - if (kvm_read_guest(its->dev->kvm, + if (kvm_read_guest_lock(its->dev->kvm, BASER_ADDRESS(baser) + index * sizeof(indirect_ptr), &indirect_ptr, sizeof(indirect_ptr))) return false; @@ -1152,8 +1153,8 @@ static void vgic_its_process_commands(struct kvm *kvm, struct vgic_its *its) cbaser = CBASER_ADDRESS(its->cbaser); while (its->cwriter != its->creadr) { - int ret = kvm_read_guest(kvm, cbaser + its->creadr, - cmd_buf, ITS_CMD_SIZE); + int ret = kvm_read_guest_lock(kvm, cbaser + its->creadr, + cmd_buf, ITS_CMD_SIZE); /* * If kvm_read_guest() fails, this could be due to the guest * programming a bogus value in CBASER or something else going |